193707721

Properties

Appears in sequences

• a(n) = least primitive factor of 2^(2n+1) - 1.at n=33A002184
• Smallest prime factor of Mersenne numbers 2^p-1, where p is prime.at n=18A016047
• Triangle read by rows formed by the prime factors of Mersenne number 2^prime(n) - 1, n >= 1.at n=31A089162
• Smallest prime factor of composite Mersenne numbers: lpf(2^p-1) where 2^p-1 is composite and p is prime.at n=9A136030
• Smallest prime factor of A135972(n), the n-th composite Mersenne number.at n=56A242016
• Prime factors of 2^A054723(n)-1, ordered by increasing n, then by increasing size of the factors.at n=22A244453
• Prime numbersat n=10749692